sitelights
08-20-2003, 06:45 PM
These regulation devices are power resistors that reduce voltage to the lamp to prevent overvoltage when using multi-tap transformers with 12, 13, 14, or 15 volt outputs. Reducing the voltage to less than 12v when using a higher output voltage allows the installer to increase voltage to the distant lamps for higher light output while insuring that the closer lamps have 12v or less. The two regulation devices tested are an old Intermatic Malibu "lamp saver" (plus similar resistors) and the recently introduced Rockscapes regulator model LVR12-15. There are no secrets in landscape lighting but there are a few tricks.
The Malibu "lamp saver" was sold as an accessory to any of their low voltage lighting kits along with replacement lamps, etc. I have not seen them displayed for many years and my memory conjures up the image of two or three to the blister pack for a couple of bucks. The unit that I have tested was purchased at least 15 years ago and has languished in the bottom of a parts bucket all that time. What brought it to mind was the introduction of the LVR12-15 and an email exchange I had with Rockscape's CEO in October 2002.
The "lamp saver" is a small ceramic block (7/8" long and 5/16" square) with a soft (not stranded or sheathed) wire lead 1 1/2" long protruding from each end. Installation was simply cutting one conductor of the fixture lead wire and attaching the device with butt splices to each end of the cut wire: two splices instead of four. All of the resistors tested are approximately the same dimensions. The test conditions for the Malibu (plus other items) and the Rockscapes LVR12-15 were the same. Using a multi-tap transformer with 12, 13, and 15v outputs, a digital volt meter, an MR-16 socket and 10, 20, 35, 42, 50, 65, and 75w lamps. Each device was wired in series: transformer output to device to lamp. Line voltage input was 122.5v and the outputs at the secondaries were 12.25v, 13.05v and 15.35v with no load. The transformer that was handy did not have a 14v tap.
The Rockscapes LVR12-15s were purchased (I bought 12) from callite.com for $6.60 each plus shipping or a unit cost of $7.43 These were the first that they ever sold and it took about two weeks from order to delivery. The LVR12-15 is a plastic box 1 5/8" long, 1 1/4" wide and 7/8" deep with two red and two black wires protruding from two top corners (along the same edge) and the "box" is potted with black epoxy resin. The wires are stranded, tinned copper 18 gauge; the "red leads to fixture" (4" long) and "black leads to power" (60" long) are pre-stripped about 1/2". The label on one side is printed "Rockscapes, LLC Chatsworth CA email: sales@rockscapes.net Regulator Model LVR 12-15 Patent Pending Input voltage 15Vac Max Load 75 watt Max" plus the wiring directions quoted above. There is a flange attached on the center line of the bottom shaped like the male side of a dovetail joint and this is probably a mounting flange perhaps used in Rockscape luminaires all of which have this device pre-installed.
The intended use of the Rockscapes LVR12-15 is marginally different from that of the Malibu item. The LVR12-15 is designed to simplify design and installation by wiring only to the 15v tap and letting the regulator do the work. Since the lamps cannot be overvolted it's a no-brainer. On "Car Talk" Click and Clack use the phrase "...unencumbered by the human thought process". The Malibu item requires a brain and cannot be installed by a trained monkey. A 00.00 volt meter (see post) is absolutely essential to apply this fix.
Both of these devices accomplish their intended use. A somewhat tedious series of tests were performed; over 160 separate voltage measurements covering 5 different regulation devices: the LVR plus a range of 4 power resistors from .5 ohms (Malibu) to .75 ohms. Every item was measured using all the voltages and all the MR-16 lamps. Rather than bore everyone with the numbers (but I will post them if asked) I will offer a narrative instead of a set of tables.
The LVR reduced all the voltages to an acceptable range (10.40 - 11.82v) but at 15v 20w the voltage was 9.20, at 35w 9.70. The LVR handled the entire range of loads with the exceptions noted. The .5 and .551 power resistors (including the original Malibu item) did as well as the LVR with the 20w load at 12 and 13v but they could not handle 15v. With a 35w load they did OK (10.04 - 11.09v at 12 and 13v; the .604 and the .75 hovered around 10v.
The designer/installer using the 15v only method and the standard Rockscape fixtures with the on-board LVRs can rest easy. Other designer/installers who have resisted being captured and held hostage by the makers of unique (no capital U) and proprietary gadgets can save big bucks by using the inexpensive .500, .551, .604 or .750 ohm resistors. A NOTE OF CAUTION! Absolutely DO NOT use these resistors with loads higher than 35w. As the wattage climbs the resistors go from warm to HOT at 50w and above. The LVR by contrast did not get appreciably warm right up to 75w. I have bought a stock of the Dale .551 (order part number RWP21FR511F).
Prior to this desk top test we installed two LVRs on a project last week. The two closest lamps (one on each side of the 10/2 loop to the transformer) were being hit with 13v using the 14v tap; the voltage dropped to 11.8v at the lamp base using the LVRs. However, a very curious occurance was brought to my attention by the client: the two LVRed luminaires did not light up when the system switched on at dusk but they came on after about 20-30 minutes. We experienced the same thing the day we were on site to make a few additions. In fact we assumed that we had bad lamps or a faulty connection at each fixture. We checked one of the fixtures with a new lamp and a re-made connection and while we were doing this the other dark fixture winked on; then the second fixture came on a minute or two later. (This was also experienced during the tests.) We removed the two LVRs and our alternate fix will be the Dale .551 item detailed above. I am going to alert Rockscapes by directing the CEO to this post. [A response was received the next (08.22.03) day: "Joe, the delay is called soft start. The soft start extends the life of the filament by not hitting the filament with 12-volts all at once." This delayed start was eliminated in subsequent iterations.] The client's perception was that two of the fixtures nearest their front door were failing to light up with the other fixtures and they were correct. How can you explain a half hour gap to the client and why should they care? If the LVRs need a warm-up period (like the "strike time" on an HID) their utility is underwhelming. If the Rockscapes LVR fixtures light up one at a time the reverse of this would be just like the Hayden "Farewell Symphony" where the musicians, in turn, blow out their music stand candles one by one until the hall is dark.
How do these things work? They turn the excess voltage into heat and while they do not add to the transformer load, someone is paying for the heat
Interestingly, Kichler's catalog lists a voltage boosting device they call "The Enhancer". These are installed like the resistors but use the voltage in the secondary cable to increase the voltage downstream. They do add to the transformer load but no technical specs are given in the catalog. I will check it out and cover this item in a future product review.
The Malibu "lamp saver" was sold as an accessory to any of their low voltage lighting kits along with replacement lamps, etc. I have not seen them displayed for many years and my memory conjures up the image of two or three to the blister pack for a couple of bucks. The unit that I have tested was purchased at least 15 years ago and has languished in the bottom of a parts bucket all that time. What brought it to mind was the introduction of the LVR12-15 and an email exchange I had with Rockscape's CEO in October 2002.
The "lamp saver" is a small ceramic block (7/8" long and 5/16" square) with a soft (not stranded or sheathed) wire lead 1 1/2" long protruding from each end. Installation was simply cutting one conductor of the fixture lead wire and attaching the device with butt splices to each end of the cut wire: two splices instead of four. All of the resistors tested are approximately the same dimensions. The test conditions for the Malibu (plus other items) and the Rockscapes LVR12-15 were the same. Using a multi-tap transformer with 12, 13, and 15v outputs, a digital volt meter, an MR-16 socket and 10, 20, 35, 42, 50, 65, and 75w lamps. Each device was wired in series: transformer output to device to lamp. Line voltage input was 122.5v and the outputs at the secondaries were 12.25v, 13.05v and 15.35v with no load. The transformer that was handy did not have a 14v tap.
The Rockscapes LVR12-15s were purchased (I bought 12) from callite.com for $6.60 each plus shipping or a unit cost of $7.43 These were the first that they ever sold and it took about two weeks from order to delivery. The LVR12-15 is a plastic box 1 5/8" long, 1 1/4" wide and 7/8" deep with two red and two black wires protruding from two top corners (along the same edge) and the "box" is potted with black epoxy resin. The wires are stranded, tinned copper 18 gauge; the "red leads to fixture" (4" long) and "black leads to power" (60" long) are pre-stripped about 1/2". The label on one side is printed "Rockscapes, LLC Chatsworth CA email: sales@rockscapes.net Regulator Model LVR 12-15 Patent Pending Input voltage 15Vac Max Load 75 watt Max" plus the wiring directions quoted above. There is a flange attached on the center line of the bottom shaped like the male side of a dovetail joint and this is probably a mounting flange perhaps used in Rockscape luminaires all of which have this device pre-installed.
The intended use of the Rockscapes LVR12-15 is marginally different from that of the Malibu item. The LVR12-15 is designed to simplify design and installation by wiring only to the 15v tap and letting the regulator do the work. Since the lamps cannot be overvolted it's a no-brainer. On "Car Talk" Click and Clack use the phrase "...unencumbered by the human thought process". The Malibu item requires a brain and cannot be installed by a trained monkey. A 00.00 volt meter (see post) is absolutely essential to apply this fix.
Both of these devices accomplish their intended use. A somewhat tedious series of tests were performed; over 160 separate voltage measurements covering 5 different regulation devices: the LVR plus a range of 4 power resistors from .5 ohms (Malibu) to .75 ohms. Every item was measured using all the voltages and all the MR-16 lamps. Rather than bore everyone with the numbers (but I will post them if asked) I will offer a narrative instead of a set of tables.
The LVR reduced all the voltages to an acceptable range (10.40 - 11.82v) but at 15v 20w the voltage was 9.20, at 35w 9.70. The LVR handled the entire range of loads with the exceptions noted. The .5 and .551 power resistors (including the original Malibu item) did as well as the LVR with the 20w load at 12 and 13v but they could not handle 15v. With a 35w load they did OK (10.04 - 11.09v at 12 and 13v; the .604 and the .75 hovered around 10v.
The designer/installer using the 15v only method and the standard Rockscape fixtures with the on-board LVRs can rest easy. Other designer/installers who have resisted being captured and held hostage by the makers of unique (no capital U) and proprietary gadgets can save big bucks by using the inexpensive .500, .551, .604 or .750 ohm resistors. A NOTE OF CAUTION! Absolutely DO NOT use these resistors with loads higher than 35w. As the wattage climbs the resistors go from warm to HOT at 50w and above. The LVR by contrast did not get appreciably warm right up to 75w. I have bought a stock of the Dale .551 (order part number RWP21FR511F).
Prior to this desk top test we installed two LVRs on a project last week. The two closest lamps (one on each side of the 10/2 loop to the transformer) were being hit with 13v using the 14v tap; the voltage dropped to 11.8v at the lamp base using the LVRs. However, a very curious occurance was brought to my attention by the client: the two LVRed luminaires did not light up when the system switched on at dusk but they came on after about 20-30 minutes. We experienced the same thing the day we were on site to make a few additions. In fact we assumed that we had bad lamps or a faulty connection at each fixture. We checked one of the fixtures with a new lamp and a re-made connection and while we were doing this the other dark fixture winked on; then the second fixture came on a minute or two later. (This was also experienced during the tests.) We removed the two LVRs and our alternate fix will be the Dale .551 item detailed above. I am going to alert Rockscapes by directing the CEO to this post. [A response was received the next (08.22.03) day: "Joe, the delay is called soft start. The soft start extends the life of the filament by not hitting the filament with 12-volts all at once." This delayed start was eliminated in subsequent iterations.] The client's perception was that two of the fixtures nearest their front door were failing to light up with the other fixtures and they were correct. How can you explain a half hour gap to the client and why should they care? If the LVRs need a warm-up period (like the "strike time" on an HID) their utility is underwhelming. If the Rockscapes LVR fixtures light up one at a time the reverse of this would be just like the Hayden "Farewell Symphony" where the musicians, in turn, blow out their music stand candles one by one until the hall is dark.
How do these things work? They turn the excess voltage into heat and while they do not add to the transformer load, someone is paying for the heat
Interestingly, Kichler's catalog lists a voltage boosting device they call "The Enhancer". These are installed like the resistors but use the voltage in the secondary cable to increase the voltage downstream. They do add to the transformer load but no technical specs are given in the catalog. I will check it out and cover this item in a future product review.